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Posted: 11/16/2008 6:22:30 PM EDT
[#1]
Sorry, can't be of any help on the BDC question, but thought that I'd bump you back to the top, maybe Bullit will catch this. On the other question, if I remember correctly the A4 version is for a 20" barrel and the M150CP is for a 14.5" barrel.
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Posted: 11/18/2008 7:14:41 PM EDT
[#2]
Update:
After a lengthy discussion with Trijicon today, I found out: Both the RCO A4 AND M4 use the same BDC. They both use a 62gr bullet at 28XX.X fps (Yes there was a .X) So basically, 2900fps. and I assume M855 are used. This made no sense to me as Trijicon claims one is for a 20" and one a 14.5" barrel. I asked them what the difference is and he could not tell me. He said they both were based off of a 62gr bullet at 2900fps (the last time I called I got a similar answer, although they said 2870fps, so the guy rounded down that time I guess.) Wierd. I guess this means the BDC matches M193 more than it does M855 according to my ballistics calculator. Any thoughts/experiences? Bullit?? |
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Posted: 11/19/2008 7:47:36 AM EDT
[#3]
Quoted:
Update: After a lengthy discussion with Trijicon today, I found out: Both the RCO A4 AND M4 use the same BDC. They both use a 62gr bullet at 28XX.X fps (Yes there was a .X) So basically, 2900fps. and I assume M855 are used. This made no sense to me as Trijicon claims one is for a 20" and one a 14.5" barrel. I asked them what the difference is and he could not tell me. He said they both were based off of a 62gr bullet at 2900fps (the last time I called I got a similar answer, although they said 2870fps, so the guy rounded down that time I guess.) Wierd. I guess this means the BDC matches M193 more than it does M855 according to my ballistics calculator. Any thoughts/experiences? Bullit?? Sorry buddy, didn't see this until now. Here are approximations for each reticle. They are based on the same bullet but the reticles are different due to the barrel length. TA31RCO-A4 FROM TIP OF CHEVRON TO: BOTTOM OF THE CHEVRON 5 MOA 1ST HASHMARK (400M) 8 MOA 2ND HASHMARK 12 MOA 3RD HASHMARK (600M) 17 MOA 4TH HASHMARK 23 MOA 5TH HASHMARK 32 MOA TA31RCO-M4 FROM TIP OF CHEVRON TO: BOTTOM OF THE CHEVRON 5 MOA 1ST HASHMARK (400M) 9 MOA 2ND HASHMARK 14 MOA 3RD HASHMARK (600M) 20 MOA 4TH HASHMARK 28 MOA 5TH HASHMARK 38 MOA |
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Posted: 11/19/2008 9:08:32 AM EDT
[#4]
Quoted:
Sorry buddy, didn't see this until now. Here are approximations for each reticle. They are based on the same bullet but the reticles are different due to the barrel length. TA31RCO-A4 FROM TIP OF CHEVRON TO: BOTTOM OF THE CHEVRON 5 MOA 1ST HASHMARK (400M) 8 MOA 2ND HASHMARK 12 MOA 3RD HASHMARK (600M) 17 MOA 4TH HASHMARK 23 MOA 5TH HASHMARK 32 MOA TA31RCO-M4 FROM TIP OF CHEVRON TO: BOTTOM OF THE CHEVRON 5 MOA 1ST HASHMARK (400M) 9 MOA 2ND HASHMARK 14 MOA 3RD HASHMARK (600M) 20 MOA 4TH HASHMARK 28 MOA 5TH HASHMARK 38 MOA Can you tell me which one of these the TA31F uses, or is it a seperate reticle all together? This is great information. |
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Posted: 11/19/2008 9:37:10 AM EDT
[#5]
Quoted:
Quoted:
Sorry buddy, didn't see this until now. Here are approximations for each reticle. They are based on the same bullet but the reticles are different due to the barrel length. TA31RCO-A4 FROM TIP OF CHEVRON TO: BOTTOM OF THE CHEVRON 5 MOA 1ST HASHMARK (400M) 8 MOA 2ND HASHMARK 12 MOA 3RD HASHMARK (600M) 17 MOA 4TH HASHMARK 23 MOA 5TH HASHMARK 32 MOA TA31RCO-M4 FROM TIP OF CHEVRON TO: BOTTOM OF THE CHEVRON 5 MOA 1ST HASHMARK (400M) 9 MOA 2ND HASHMARK 14 MOA 3RD HASHMARK (600M) 20 MOA 4TH HASHMARK 28 MOA 5TH HASHMARK 38 MOA Can you tell me which one of these the TA31F uses, or is it a seperate reticle all together? This is great information. TA31F would be very close (maybe the same, I would need to look it up) to the RCO-M4. |
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Posted: 11/19/2008 11:40:24 AM EDT
[#6]
Quoted:
Quoted:
Update: After a lengthy discussion with Trijicon today, I found out: Both the RCO A4 AND M4 use the same BDC. They both use a 62gr bullet at 28XX.X fps (Yes there was a .X) So basically, 2900fps. and I assume M855 are used. This made no sense to me as Trijicon claims one is for a 20" and one a 14.5" barrel. I asked them what the difference is and he could not tell me. He said they both were based off of a 62gr bullet at 2900fps (the last time I called I got a similar answer, although they said 2870fps, so the guy rounded down that time I guess.) Wierd. I guess this means the BDC matches M193 more than it does M855 according to my ballistics calculator. Any thoughts/experiences? Bullit?? Sorry buddy, didn't see this until now. Here are approximations for each reticle. They are based on the same bullet but the reticles are different due to the barrel length. TA31RCO-A4 FROM TIP OF CHEVRON TO: BOTTOM OF THE CHEVRON 5 MOA 1ST HASHMARK (400M) 8 MOA 2ND HASHMARK 12 MOA 3RD HASHMARK (600M) 17 MOA 4TH HASHMARK 23 MOA 5TH HASHMARK 32 MOA TA31RCO-M4 FROM TIP OF CHEVRON TO: BOTTOM OF THE CHEVRON 5 MOA 1ST HASHMARK (400M) 9 MOA 2ND HASHMARK 14 MOA 3RD HASHMARK (600M) 20 MOA 4TH HASHMARK 28 MOA 5TH HASHMARK 38 MOA What round is this supposed to even approximate? It comes close to matching NOTHING the military is using. At 800m that is 256" drop. M193 only drops 236" and M855 around 200". So what optic should I get for launching M193 or m855 through an A4 20" ? This is confusing 
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Posted: 11/19/2008 11:48:45 AM EDT
[#7]
Quoted:
Quoted:
Quoted:
Update: After a lengthy discussion with Trijicon today, I found out: Both the RCO A4 AND M4 use the same BDC. They both use a 62gr bullet at 28XX.X fps (Yes there was a .X) So basically, 2900fps. and I assume M855 are used. This made no sense to me as Trijicon claims one is for a 20" and one a 14.5" barrel. I asked them what the difference is and he could not tell me. He said they both were based off of a 62gr bullet at 2900fps (the last time I called I got a similar answer, although they said 2870fps, so the guy rounded down that time I guess.) Wierd. I guess this means the BDC matches M193 more than it does M855 according to my ballistics calculator. Any thoughts/experiences? Bullit?? Sorry buddy, didn't see this until now. Here are approximations for each reticle. They are based on the same bullet but the reticles are different due to the barrel length. TA31RCO-A4 FROM TIP OF CHEVRON TO: BOTTOM OF THE CHEVRON 5 MOA 1ST HASHMARK (400M) 8 MOA 2ND HASHMARK 12 MOA 3RD HASHMARK (600M) 17 MOA 4TH HASHMARK 23 MOA 5TH HASHMARK 32 MOA TA31RCO-M4 FROM TIP OF CHEVRON TO: BOTTOM OF THE CHEVRON 5 MOA 1ST HASHMARK (400M) 9 MOA 2ND HASHMARK 14 MOA 3RD HASHMARK (600M) 20 MOA 4TH HASHMARK 28 MOA 5TH HASHMARK 38 MOA What round is this supposed to even approximate? It comes close to matching NOTHING the military is using. At 800m that is 256" drop. M193 only drops 236" and M855 around 200". So what optic should I get for launching M193 or m855 through an A4 20" ? This is confusing  As I mentioned, these are only approximations as I cannot give out the actual MOA dimensions. Our reticles are designed around the M855 round and ballistic data given to us by the military as well as our other customers. Sorry if this doesn't help you, it works great for the Army and Marines 
ETA - if you are using a 20" barrel use the A4. I really don't think you will notice if the BDC is slightly off given the round you choose. |
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Posted: 11/19/2008 12:46:15 PM EDT
[#8]
Quoted:
Quoted:
Quoted:
Quoted:
Update: After a lengthy discussion with Trijicon today, I found out: Both the RCO A4 AND M4 use the same BDC. They both use a 62gr bullet at 28XX.X fps (Yes there was a .X) So basically, 2900fps. and I assume M855 are used. This made no sense to me as Trijicon claims one is for a 20" and one a 14.5" barrel. I asked them what the difference is and he could not tell me. He said they both were based off of a 62gr bullet at 2900fps (the last time I called I got a similar answer, although they said 2870fps, so the guy rounded down that time I guess.) Wierd. I guess this means the BDC matches M193 more than it does M855 according to my ballistics calculator. Any thoughts/experiences? Bullit?? Sorry buddy, didn't see this until now. Here are approximations for each reticle. They are based on the same bullet but the reticles are different due to the barrel length. TA31RCO-A4 FROM TIP OF CHEVRON TO: BOTTOM OF THE CHEVRON 5 MOA 1ST HASHMARK (400M) 8 MOA 2ND HASHMARK 12 MOA 3RD HASHMARK (600M) 17 MOA 4TH HASHMARK 23 MOA 5TH HASHMARK 32 MOA TA31RCO-M4 FROM TIP OF CHEVRON TO: BOTTOM OF THE CHEVRON 5 MOA 1ST HASHMARK (400M) 9 MOA 2ND HASHMARK 14 MOA 3RD HASHMARK (600M) 20 MOA 4TH HASHMARK 28 MOA 5TH HASHMARK 38 MOA What round is this supposed to even approximate? It comes close to matching NOTHING the military is using. At 800m that is 256" drop. M193 only drops 236" and M855 around 200". So what optic should I get for launching M193 or m855 through an A4 20" ? This is confusing As I mentioned, these are only approximations as I cannot give out the actual MOA dimensions. Our reticles are designed around the M855 round and ballistic data given to us by the military as well as our other customers. Sorry if this doesn't help you, it works great for the Army and Marines 
ETA - if you are using a 20" barrel use the A4. I really don't think you will notice if the BDC is slightly off given the round you choose. I am coming up with around a meter off in elevation at 800m using tha A4 and the M855. Perhapse I am calculating things wrong. |
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Posted: 11/19/2008 12:49:56 PM EDT
[#9]
Quoted:
Quoted:
Quoted:
Quoted:
Quoted:
Update: After a lengthy discussion with Trijicon today, I found out: Both the RCO A4 AND M4 use the same BDC. They both use a 62gr bullet at 28XX.X fps (Yes there was a .X) So basically, 2900fps. and I assume M855 are used. This made no sense to me as Trijicon claims one is for a 20" and one a 14.5" barrel. I asked them what the difference is and he could not tell me. He said they both were based off of a 62gr bullet at 2900fps (the last time I called I got a similar answer, although they said 2870fps, so the guy rounded down that time I guess.) Wierd. I guess this means the BDC matches M193 more than it does M855 according to my ballistics calculator. Any thoughts/experiences? Bullit?? Sorry buddy, didn't see this until now. Here are approximations for each reticle. They are based on the same bullet but the reticles are different due to the barrel length. TA31RCO-A4 FROM TIP OF CHEVRON TO: BOTTOM OF THE CHEVRON 5 MOA 1ST HASHMARK (400M) 8 MOA 2ND HASHMARK 12 MOA 3RD HASHMARK (600M) 17 MOA 4TH HASHMARK 23 MOA 5TH HASHMARK 32 MOA TA31RCO-M4 FROM TIP OF CHEVRON TO: BOTTOM OF THE CHEVRON 5 MOA 1ST HASHMARK (400M) 9 MOA 2ND HASHMARK 14 MOA 3RD HASHMARK (600M) 20 MOA 4TH HASHMARK 28 MOA 5TH HASHMARK 38 MOA What round is this supposed to even approximate? It comes close to matching NOTHING the military is using. At 800m that is 256" drop. M193 only drops 236" and M855 around 200". So what optic should I get for launching M193 or m855 through an A4 20" ? This is confusing As I mentioned, these are only approximations as I cannot give out the actual MOA dimensions. Our reticles are designed around the M855 round and ballistic data given to us by the military as well as our other customers. Sorry if this doesn't help you, it works great for the Army and Marines
ETA - if you are using a 20" barrel use the A4. I really don't think you will notice if the BDC is slightly off given the round you choose. I am coming up with around a meter off in elevation at 800m using tha A4 and the M855. Perhapse I am calculating things wrong. I'll look into it further, I just pulled the info from the reticle print.... |
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Posted: 11/19/2008 1:16:27 PM EDT
[#10]
Quoted:
What round is this supposed to even approximate? It comes close to matching NOTHING the military is using. At 800m that is 256" drop. M193 only drops 236" and M855 around 200". So what optic should I get for launching M193 or m855 through an A4 20" ? This is confusing 
The numbers bullitt5172 posted are almost dead on compared to the numbers my ballistics calculator cranks out. Even shooting M193 through a 14.5" barrel isn't a factor on man sized targets until you go past 500m. M193 through a 20" barrel? Get the A4 and stop worrying. 
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Posted: 11/19/2008 1:34:49 PM EDT
[#11]
Quoted:
Quoted:
What round is this supposed to even approximate? It comes close to matching NOTHING the military is using. At 800m that is 256" drop. M193 only drops 236" and M855 around 200". So what optic should I get for launching M193 or m855 through an A4 20" ? This is confusing
The numbers bullitt5172 posted are almost dead on compared to the numbers my ballistics calculator cranks out. Even shooting M193 through a 14.5" barrel isn't a factor on man sized targets until you go past 500m. M193 through a 20" barrel? Get the A4 and stop worrying. Ok, I am the retard here. ACOG=M, I am using Y. I will re-figure in M and I bet it will be pretty close to dead on. :( Thanks Bullit for the info!!! ETA: At 600y/m pretty much any round is within MOA using the A$ ACOG and 20" barrel. Past 600, the only way to get anywhere near the BDC (within 2-3 MOA at 800) is to use M193 and use the ACOG in Y instead of M. That will keep you to within 1MOA of your target from 0-800 yards. This was calculated using M193=3250/.243 and M855=3100/.304. If I were to use M855 and calculate in meters, I would be roughly 2' off at 800m If I use M193 and use y, I will be within about 6" at 800 yards. (Basically pretend the BDC is set for yards and not meters, use M193, and dont worry about it). |
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Posted: 11/19/2008 4:46:16 PM EDT
[#12]
Quoted:
Quoted:
Quoted:
What round is this supposed to even approximate? It comes close to matching NOTHING the military is using. At 800m that is 256" drop. M193 only drops 236" and M855 around 200". So what optic should I get for launching M193 or m855 through an A4 20" ? This is confusing
The numbers bullitt5172 posted are almost dead on compared to the numbers my ballistics calculator cranks out. Even shooting M193 through a 14.5" barrel isn't a factor on man sized targets until you go past 500m. M193 through a 20" barrel? Get the A4 and stop worrying. Ok, I am the retard here. ACOG=M, I am using Y. I will re-figure in M and I bet it will be pretty close to dead on. :( Thanks Bullit for the info!!! ETA: At 600y/m pretty much any round is within MOA using the A$ ACOG and 20" barrel. Past 600, the only way to get anywhere near the BDC (within 2-3 MOA at 800) is to use M193 and use the ACOG in Y instead of M. That will keep you to within 1MOA of your target from 0-800 yards. This was calculated using M193=3250/.243 and M855=3100/.304. If I were to use M855 and calculate in meters, I would be roughly 2' off at 800m If I use M193 and use y, I will be within about 6" at 800 yards. (Basically pretend the BDC is set for yards and not meters, use M193, and dont worry about it). Whewww,, saves me having to go through the print again
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Posted: 11/19/2008 5:20:36 PM EDT
[#13]
Quoted:
Quoted:
Quoted:
Quoted:
What round is this supposed to even approximate? It comes close to matching NOTHING the military is using. At 800m that is 256" drop. M193 only drops 236" and M855 around 200". So what optic should I get for launching M193 or m855 through an A4 20" ? This is confusing
The numbers bullitt5172 posted are almost dead on compared to the numbers my ballistics calculator cranks out. Even shooting M193 through a 14.5" barrel isn't a factor on man sized targets until you go past 500m. M193 through a 20" barrel? Get the A4 and stop worrying. Ok, I am the retard here. ACOG=M, I am using Y. I will re-figure in M and I bet it will be pretty close to dead on. :( Thanks Bullit for the info!!! ETA: At 600y/m pretty much any round is within MOA using the A$ ACOG and 20" barrel. Past 600, the only way to get anywhere near the BDC (within 2-3 MOA at 800) is to use M193 and use the ACOG in Y instead of M. That will keep you to within 1MOA of your target from 0-800 yards. This was calculated using M193=3250/.243 and M855=3100/.304. If I were to use M855 and calculate in meters, I would be roughly 2' off at 800m If I use M193 and use y, I will be within about 6" at 800 yards. (Basically pretend the BDC is set for yards and not meters, use M193, and dont worry about it). Whewww,, saves me having to go through the print again Meh, I wish I could get my hands on the print, but it seems to be internal info only :( |
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